第六节结肠癌（Sixth colon cancer）.doc

第六节结肠癌（Sixth colon cancer）第六节结肠癌结肠癌（结肠癌）是胃肠道中常见的恶性肿瘤，以41 ^岁发病率高在我国65近20年来尤其在大城市，发病率明显上升，且有结肠癌多于直肠癌的趋势从病因看半数以上来自腺瘤癌变，从形态学上可见到增生、腺瘤及癌变各阶段（图40-13）以及相应的染色体改变随分子生物学技术的发展，同时存在的分子事件基因表达亦渐被认识，从中明确癌的发生发展是一个多步骤、多阶段及多基因参与的细胞遗传性疾病大肠癌时从细胞向癌变演进，从腺瘤一癌序列约经历10 ^ - 15年，在此癌变过程中，遗传突变包括癌基因激活（K－ras、c-myc、EGFR）、抑癌基因失活（APC、DCC，p53）、错配修复基因突变（hmshi，何梁何利，pms1，PMS2，GTBP）及基因过度表姨发减一F = F一尹1E）所日马所有~目APC K-ras基因DCC P53 nm23？MMR染色体改变去甲基MMR5q 12q 18q 17q突变·缺失突变突变？缺失突变·缺失缺失·突变？图40-13大肠癌变过程模式图（错配修复基因）：hMSH 2、hMLH 1、创新1创新2达（COX-2，CD44v）O APC基因失活致杂合性缺失，APC /汗连环通路启动促成腺瘤进程；错配修复基因突变致基因不稳定，可出现遗传性非息肉病结肠癌（遗传性非—息肉性结肠癌，HNPCC）综合征。

结肠癌病因虽未明确，但其相关的高危因素渐被认识，如过多的动物脂肪及动物蛋白饮食，缺乏新鲜蔬菜及纤维素食品；缺乏适度的体力活动遗传易感性在结肠癌的发病中也具有重要地位，如遗传性非息肉性结肠癌的错配修复基因突变携带的家族成员，应视为结肠癌的一组高危人群有些病如家族性肠息肉病，已被公认为癌前期疾病；结肠腺瘤、溃疡性结肠炎以及结肠血吸虫病肉芽肿，与结肠癌的发生有较密切的关系病理与分型根据肿瘤的大体形态可区分为：1肿块型（图40-14）肿瘤向肠腔内生长，好发于右侧结肠，特别是盲肠浸润型（图40-15）沿肠壁浸润，容易引起肠腔狭窄和肠梗阻，多发生于左侧结肠溃疡型（图40-16）其特点是向肠壁深层生长并向周围浸润，是结肠癌常见类型图40-14肿块型结肠癌显微镜下组织学分类较常见的为：①腺癌：占结肠癌的大多数②粘液癌：预后较腺③未分化癌：易侵人小血管和淋巴管，预后最差临床病理分期分期目的在于了解肿瘤发展过程，指导拟定治疗方案及估计预后国M + }际一般仍沿用改良的公爵分期及UICC TNM分期法提出的根据我国对公爵法的补充，分为：癌仅限于肠壁内为公爵穿透肠壁侵人期浆膜或/及浆膜外，但无淋巴结转移者为B期。

有淋巴结转移者为C期，其中淋巴结转移仅限于癌肿附近如结肠壁及结肠旁淋巴结者为C1期；转移至系膜和系膜根部淋巴结者为C：期已有远处转移或腹腔转移，或广泛侵及邻近脏器无法切除者为1之期TNM分期法：T代表原发肿瘤，TX为无法估计原发肿瘤无原发肿瘤证据为来；原位癌为T；G；肿瘤侵及粘膜肌层与粘膜下层为T1；侵及固有肌层为TZ；穿透肌层至浆膜下为T3；Penetrating dirtPeritoneum or invasion of other organs or tissues is T4.N was regional lymph node, N, and no lymph node could be estimated; no lymph node metastasis was No; lymph node metastasis was 1-3One was N, and the other 4 and more than 4 lymph nodes were NzoM for distant metastasis, distant metastasis can not be estimated for MX; no distant metastasis to distant metastasis for all quack; M,.TNM staging compared with Dukes staging is shown in table 40-10Table 40-1 comparison of TNM staging with Dukes stagingTNM stagingDukes stagingNcTis TITZ PlushOIAny T N,NzAny T N MColon cancer is mainly lymphatic metastasis, first to the colon wall and the colon lymph node, and then to the mesenteric vascular around and intestinalMesenteric lymph node. Hematogenous metastasis is more common in the liver, followed by lung, bone, etc.. Colon cancer can also be directly infiltrated into the vicinityOrgan. Such as the sigmoid colon, bladder, uterus, often invade ureter. Transverse colon cancer can invade the stomach wall, and even form the interior.Exfoliated cancer cells can also be transferred in peritoneal implants.The clinical manifestation of CRC is that it usually has no special symptoms in the early stage of development. The main symptoms are following symptoms:1. the change of defecation habit and fecal character is usually the earliest symptom. Most of them were increased defecation frequency and abdomenContaining blood, pus, or mucus in the stool.The abdominal pain is one of the 2. early symptoms, often persistent pain positioning is not clear, or only for abdominal discomfort or abdominalDistension of the abdomen and the presence of intestinal obstruction are aggravated by abdominal pain or paroxysmal angina.3., the abdominal mass is mostly tumor body itself, and sometimes may be obstruction in the proximal gut cavity fecal accumulation. Most of the lumps are hard,Nodular. As for the transverse and sigmoid colon cancer can have certain activity. If the cancer penetrates the concurrent infection, the tumor is solidDefinite and marked tenderness.4., intestinal obstruction symptoms are generally colon cancer in the middle and late symptoms, mostly chronic, incomplete intestinal obstruction, the LordThe symptoms are bloating and constipation. Abdominal pain or paroxysmal angina. When a complete obstruction occurs, the symptoms are exacerbated. Left colonCancer can sometimes be acute and complete colonic obstruction is the first symptom.Be reluctant to leaveDip in the fragrance, look forward to L5., systemic symptoms due to chronic bleeding, cancer ulceration, infection, toxins absorption, etc., patients can appear anemia and disappearLean, weak, low heat, etc. The disease may occur late hepatomegaly, jaundice, edema, ascites, rectal tumor, supraclavicular concaveLymph node enlargement and cachexia.Because of the pathological type and location of the cancer, the clinical manifestations are different. In general, right colon cancer is characterized by systemic symptoms,Anemia, abdominal mass were the main manifestations of left colon cancer with intestinal obstruction, constipation, diarrhea, hematochezia and other symptoms.The early symptoms of colon cancer are not obvious and easily overlooked. Any person who is over 40 years of age and any of the following shall be listed asHigh risk population: OI level 。